From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22F59C433F5 for ; Mon, 11 Apr 2022 16:11:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242730AbiDKQN4 (ORCPT ); Mon, 11 Apr 2022 12:13:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43542 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1348119AbiDKQNr (ORCPT ); Mon, 11 Apr 2022 12:13:47 -0400 Received: from mail-wr1-x430.google.com (mail-wr1-x430.google.com [IPv6:2a00:1450:4864:20::430]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0A68920BF2 for ; Mon, 11 Apr 2022 09:10:51 -0700 (PDT) Received: by mail-wr1-x430.google.com with SMTP id t1so6060771wra.4 for ; Mon, 11 Apr 2022 09:10:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=6wind.com; s=google; h=message-id:date:mime-version:user-agent:reply-to:subject :content-language:to:cc:references:from:organization:in-reply-to :content-transfer-encoding; bh=ce5fu7ycn7dUXlc9MmLst+yQYHhyd+tclVQECLvk1js=; b=YSoxKpBQ27pJC/NUYM0t6og3xSn8vpXW+/+d6wALd3rvHLcuIT+n1KEhFkgbRQZV6O mawSArsbRGji48AE+AP4hViCE2vNxqT/FcYsLSQFJSHZ8KhC260VUqFtBA5ouNQNUCwA xfkDu6VkhuRsIBe/lmqnVtGN0wc5CSpFhj6OmLrskSGrlZB5vQLDPHmJZMqCNOpPBoeU 8kksghGHey8wzO2YeUdzQ6xxXILIBG7GPdrIF12SmWwicPEqHNXPXvPlZZLHEAzyXV83 M3b72MTX4pxHyHTSghLecN/6S56DDbGc74rDvZhTz/UrLu4SAUNHhZbyfXjg7wtBTUm4 KLiA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:reply-to :subject:content-language:to:cc:references:from:organization :in-reply-to:content-transfer-encoding; bh=ce5fu7ycn7dUXlc9MmLst+yQYHhyd+tclVQECLvk1js=; b=ygAcJXcGhGImscz4kZaYRVjCPAjNw8dSqnro7loa+6J/J9sFHGxp30+QOiQcf8LA60 TvtN0hEvdhpAGXrWZwnjNw4ZHJ+pK3i4ddec3vArbJqWzBoyvhnd4SpagT6Rl/O7jsVa 7b9Fvq3OVkuwmcWWye0j+GY00GGOsAnJJUcKU4lsy85eGUkpct9QRHoM9ia/aaU+GXyN t/dzc3iHySyTPvB1t5T8DGAqPkQ/WPE4D0B06DgmmxSYln78qUxsvKUgNWCp+LUChTvi r1md8EUgTa1M+9P1ZgT5umaUH2LLpaXBi1xHoeax5bH4H2jOLcTzL2a4q1XpZ7YpRQ3e HbOg== X-Gm-Message-State: AOAM532QdW0PLL4klDUaS5MqcdliWEpz0RtNLeOZ7Hts+g/cx+6apFdY dKjWIIs66ASQWuNG3vEWYJVTEw== X-Google-Smtp-Source: ABdhPJxJzT+c7Uqvio4omdC+uK2QKBidQlv52qRyZIzmxQpD85bRX+iO/w3anJTAY/+sqhOdQXEnVw== X-Received: by 2002:adf:f7cd:0:b0:207:a25c:24c4 with SMTP id a13-20020adff7cd000000b00207a25c24c4mr7820486wrq.528.1649693450469; Mon, 11 Apr 2022 09:10:50 -0700 (PDT) Received: from ?IPV6:2a01:e0a:b41:c160:4d92:8b8b:5889:ee2f? ([2a01:e0a:b41:c160:4d92:8b8b:5889:ee2f]) by smtp.gmail.com with ESMTPSA id g16-20020a05600c4ed000b0038ceb0b21b4sm21565794wmq.24.2022.04.11.09.10.49 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 11 Apr 2022 09:10:49 -0700 (PDT) Message-ID: <41a58ead-9a14-c061-ee12-42050605deff@6wind.com> Date: Mon, 11 Apr 2022 18:10:49 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Reply-To: nicolas.dichtel@6wind.com Subject: Re: What is the purpose of dev->gflags? Content-Language: en-US To: Vladimir Oltean Cc: Jakub Kicinski , netdev@vger.kernel.org, "David S. Miller" , Paolo Abeni References: <20220408183045.wpyx7tqcgcimfudu@skbuf> <20220408115054.7471233b@kernel.org> <20220408191757.dllq7ztaefdyb4i6@skbuf> <797f525b-9b85-9f86-2927-6dfb34e61c31@6wind.com> <20220411153334.lpzilb57wddxlzml@skbuf> <20220411154911.3mjcprftqt6dpqou@skbuf> From: Nicolas Dichtel Organization: 6WIND In-Reply-To: <20220411154911.3mjcprftqt6dpqou@skbuf> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Le 11/04/2022 à 17:49, Vladimir Oltean a écrit : > On Mon, Apr 11, 2022 at 05:43:01PM +0200, Nicolas Dichtel wrote: >> >> Le 11/04/2022 à 17:33, Vladimir Oltean a écrit : >> [snip] >>> Would you agree that the __dev_set_allmulti() -> __dev_notify_flags() >>> call path is dead code? If it is, is there any problem it should be >>> addressing which it isn't, or can we just delete it? >> I probably miss your point, why is it dead code? > > Because __dev_set_allmulti() doesn't update dev->gflags, it means > dev->gflags == old_gflags. In turn, it means dev->gflags ^ old_gflags, > passed to "gchanges" of __dev_notify_flags(), is 0. I didn't take any assumptions on dev->gflags because two functions are called with dev as parameter (dev_change_rx_flags() and dev_set_rx_mode()). Even if __dev_notify_flags() is called with 0 for the last arg, it calls notifiers. Thus, this is not "dead code".